Unable to track 50nm and just took off aircraft

[skyspotter]

my 1st antenna was the so called 8 legged spider using #12 wire.. twas tracking like 140-150nm from my location including all approaching aircraft. Am less than 5 miles from the airport. Now i made another one..the same design but this time im using #14 wire .. what i observed was.. i hardly track planes from 50nm and approaches. BUT it can track distant aircraft like 160-180nm.. Wondering whats the cause of being blind on near aircraft.. Hoping for your kind response regarding.

[SpaxmoidJAm]

There are a few things that will effect reception like you describe, and it could be any of them.

Being that close to an airport (especially a busy one) you are going to have to make a choice between close range or distance tuning because of the loudness of the signals drowning out the distant ones.



It could just be that the signal is louder, and now at close range the dongle is saturated and cant pick out the aircraft. think hifi turned up to loud the only stuff you can make out is the quiet bits.
To test this i would start by lowering the gain in small increments over a period of time hours to see when you start seeing close range aircraft again( if you do). you might find a happy medium.

Lastly and this is probably it, the amount you bend the ground plane legs can have a significant effect on how the antenna receives, it might be that your new one is looking up more than your previous hence you see aircraft at range.

tip: when you are trying to straiten the wire use two pairs of pliers one on each end of the wire and pull as hard as you can it will stretch the wire a little and straiten it.

Also the length of the centre (main antenna) should be measure from the ground plane and not the dialectic of the connector you are using.


Hopefully that makes sense i edited it a few times.

[skyspotter]

Great! Thank you so much for your time. I was just observing the performance since then. The weather is overcast and a bit bad since i installed it. i didnt bother to put it down since its picking up farther and distant packets of signal. It could may be how i bent the radials, the last one was like 45-55 degs and the new one is between 35-45degs.. or the length of the elements. i know it will have a big effect with its gain and pattern.